A computer logic element is composed of, for example, a silicon transistor, and in this silicon transistor, electrical conductivity of an electronic device including a semiconductor junction interface is changed by injecting electrons or holes into the semiconductor junction interface, to control an electric current flowing in the electronic device (refer to Non-Patent Document 1).
Here, (a) to (e) in FIG. 5 show diagrams for explanation of a junction interface of a conventional silicon transistor. The electronic structure of a p-n junction shown in FIG. 5(a) will be described. As shown in FIG. 5(b), impurity levels respectively occur in the vicinity of their valence bands and conductive bands in the p-type and n-type semiconductors, and holes and conduction electrons are generated respectively in the valence bands and the conductive bands. The electrons move until the Fermi levels of both sides match each other after bonding the both sides, to provide a level distribution as shown in FIG. 5(c). As a result, in the vicinity of the junction part, the electrons in the conductive band of the n-type are coupled with the holes in the valence band of the p-type, to generate a depletion layer without conductive charges (FIG. 5(d)). At a place where there are conductive charges, its electric potential is uniform in the same way as that in metal, however, an electric potential distribution as shown in FIG. 5(e) is brought about in a depletion layer due to its space charge, which causes a step in the electric potential. This is called a potential barrier.    Non-Patent Document 1: Soshin Chikazumi, “Introduction to Solid State Science,” Shokabo Publishing Co., Ltd., 1999, p. 178, FIG. 9-3    Non-Patent Document 2: N. Ikeda et al., “Ferroelectricity from iron valence ordering in the charge-frustrated system LuFe2O4,” Nature, Vol. 436, No. 7054, pp. 1136-1138 (2005)    Non-Patent Document 3: N. Ikeda et al., “Charge Frustration and Dielectric Dispersion in LuFe2O4,” Journal of the Physical Society of Japan, Vol. 69, No. 5, pp. 1526-1532 (2000)